In a conventional sealing device with a resin seal lip (such as shown in FIG. 9), a washer-shaped resin ring 100 is formed, the outer diameter side of the resin ring 100 is assembled with a device body 101, and the inner end of the resin ring 100 is contacted in a sealing manner to an objective member, thus forming a resin seal lip 102.
The resin ring 100 is formed by cutting a cylindrical resin material 103 so as to have a conical washer-like shape so that the resin seal lip 102 is preliminarily provided with an inclination so as to facilitate formation thereof.
However, in the described prior art, when the a cylindrical resin material 103 is cut away in a conical shape, a thin edge portion 104 having a sharp angle .beta. smaller than 90.degree. is formed at an end portion of the resin ring 100. Since this thin edge portion 104 is easily deformable, it is difficult to handle the same.
In the case of a compound type sealing device, as shown in FIG. 9(c), having a seal lip 105 formed of a rubber like elastic material and a resin seal lip 102, when the rubber like elastic seal lip 105 is molded, the resin ring 100 is inserted and the assembling of the resin ring 100 and the molding thereof are carried out at the same time as shown in FIG. 10(a). At the completion of the molding and the opening of the mold, the resin ring 100 separates from the rubber like elastic seal lip 105 due to its elastic restoring force and falls down to an inner diameter side so as to have an interference.
However, the rubber base material 106 fluidized at the molding formation time extends around so as to bite the edge portion 104, so that, when the edge portion 104 has a sharp end, a go-round portion 107 engages the edge portion 104 of the resin ring 100 and the resin seal lip 105 sharply turns to the inner diameter side (see FIG. 10(b)).
Further, in a case where the resin seal lip 105 returns, when a shaft is inserted, the front end of the resin seal lip 102 is interferred with by the rubber like elastic seal lip 105. The rubber like elastic seal lip 105 widens and acts in a direction reducing the interference, so that the reliance of the rubber like elastic seal lip 105 is lowered (see FIG. 10(c)).
The present invention was conceived to solve the above problems of the prior art and aims to provide a sealing device and a method of munufacturing the same capable of improving a handling ability thereof and preventing an operational defect at a time of the integral molding with the rubber like elastic seal lip by effecting a chamfering working to the edge portion of a resin ring so as to provide a conical washer shape.